Shark's Sense of Smell Tested

In the latest issue of Current Biology, a team of American researchers from Florida and Massachusetts have tested the way that sharks sense of smell works in an innovative and amusing experiment. It is well known that sharks have a phenomenal sense of smell, being able to detect prey from great distances. It was previously assumed that sharks measure the the strongest smell, from the left or the right nostril, to align themselves with the source. The researchers investigated this by wiring up the nostrils of dogsharks to with tubes containing squid odour. The right nostril was given the smell of squid first, then half a second later the left nostril was given an even stronger smell of squid. It was found that the shark would swim in the direction of the first source of squid odour even though it was the weaker one. It is thought the reason for this is that ocean water currents can be very chaotic and it is more reliable to follow the direction of the smell that was first detected in order to get the food.

Microbial Art

Last week an undergraduate student in my laboratory had to throw out a stack of Petri dishes because they had been contaminated and some mould was growing on them. One of the moulds was a large, black six sided and quite frightening looking structure. This led me to think about the recent popularity of microbiological art. It is common in laboratories to grow cultures of bacteria on some kind of gel containing nutrients, this can have the potential to be used to make beautifully images in a wonderful combination of art and science. The picture above shows bacteria that have florescent properties, this has been quite skilfully been used to make a beach scene.

The site “Microbial Art” is dedicated to this subject and has a lot of information on the artists and scientists involved in these kind of projects.

“Cooked brains” also has a feature on the work of an Israeli scientist, one of my favourites is shown bellow.

Also I recommend an article on the subject by the Society For General Microbiology entitled “The Aesthetic Microbe”.

The Conservation of Evolutionary Interactions

Animals, plants and other organisms heave interacted with different species in one way or another for millions of years. These interactions, such as eating each other or competing for living space is thought to be a major force in causing evolution to take place. Until recently these ecological interactions had have only been studied on a few specific groups of organisms such as a few parasites. A group of Spanish scientists have attempted to improve this by looking at evolutionary ecological comparisons between 116 different species, covering a diverse range of organisms across all major known groups. They used a complicated form of statistical analysis, a little bit like an extremely complicated food web, along with the know evolutionary distance of various organisms.

They found that the previous research on specialist ecological interactions appeared to still hold true when scaled up to general ecological interactions involving a wide range of species.

The study was published in the journal Nature:

Reference: Gomez, J.M., Verdu, M. and Perfectti, F. (2010) Ecological interactions are evolutionarily conserved

across the entire tree of life. Nature. 465, 918-922

Free Invertebrate Anatomy Laboratory Protocols

Richard Fox of Lander University has been generous enough to provide laboratory protocols for the dissection and anatomical observation of 112 different invertebrate species. The guides cover all major invertebrate phyla and, although the species used are usually the ones most easily available to people in the United States, the plans are clear and flexible enough that they can be easily modified for use with local species. I personally used these to improve my understanding of mollusc species and I used their guides for oysters, squid and sea slugs. But they pretty much have everything here.

Invertebrate Anatomy Online

Is The World Cup Trophy Really Solid Gold?

The golden trophy depicting two figures holding up the globe is one of the most iconic images in sport. The FIFA football world cup is currently under-way and at the end of the tournament the winning team's captain will be allowed one of the greatest honours in sport: to hold the solid gold trophy above his head. But is it really solid gold? Football's governing body, FIFA, claims so but Professor Martyn Poliakoff from the chemistry department of the University of Nottingham claims that it could not be solid gold as the trophy would weigh about as much as an adult man and be too soft to maintain its shape. It must therefore be an alloy of gold and is probably partially hollow, most likely in the globe portion as it would really be a terrible waste of gold if it wasn't. You can watch the full video below, but I recommend you visit www.periodicvideos.com to see this and many other entertaining chemistry videos by Professor Poliakoff and his colleagues.




The Periodic Table of Videos

Free Lectures from Berkeley University

The University of Berkeley in California has, for a few year now, taped many of the lectures in various science courses, so that students can view them again or catch up on lectures they missed. freevideolectures.com has a selection of many lectures from several courses in Berkeley, as well as a few other universities. At the time of writing there were first-year lectures in chemistry, biology and physics, as well as more advanced lectures in specialized topics like cell biology and astrophysics. They have the full lectures from the courses and some courses have about 40 hours worth of material, so if you wanted the luxury of a Berkeley education without having to pay for it, this could help you...a little bit.

A few of the lecture series available:

General Chemistry, Spring 2010
General Biology, Spring 2010
Introduction to Physics, Fall 2008